The aim of this prospective epidemiologic study is to examine the relation of physical activity and/or physical fitness to health in a defined population of men and women in the middle to later years of life. Health is broadly defined and encompasses measures of cause-specific and all-cause mortality, non-fatal diseases, and functional health status. The study population is 8,290 women and 28,315 men (as of early 1992) who were examined at least once at a preventive medicine clinic during the interval 1970 to 1991. Total follow-up in the proposed project will reach approximately 100,000 woman-years and 372,000 man-years by 1995, which by conservative estimates should yield approximately 1,200 deaths for analyses. The database contains demographic, behavioral, and clinical data from the examination, health habit and health status measurements from mail surveys, and mortality information from official death certificates. We propose to continue to build this database by extending mortality follow-up for an additional five years, and by conducting another mail-back survey to monitor non-fatal disease and functional health status. A major focus of our current work to be continued in the proposed research is to evaluate the relation of activity and/or fitness to function in older individuals. Current analyses show higher rates of self-reported functional limitations in routine activities (recreational, household, daily, and personal care activities) in men and women who had low levels of physical fitness at baseline, when compared with their more fit peers. We propose to collect additional data on function in the next mail survey, which will permit observation of the relation of activity and/or fitness to change in functional health status. Other planned analyses will evaluate activity and/or fitness (and change in those antecedent variables) in relation to risk of fatal and non-fatal disease. The extended follow-up, with the greater number of deaths, will allow for more detailed analyses on cause- specific mortality. Specific causes of primary interest are prostate, lung, and breast cancers, stroke, and acute myocardial infarction. An important strength of the study is the defined population (with a substantial number of women) on whom we have an objective measure of physical fitness from a maximal exercise treadmill test. This offers an advantage over studies in which only self-reports of physical activity are available as an indication of a sedentary lifestyle. The extensive database permits control for possible confounding variables such as smoking status, blood lipids, body composition, blood pressure, other clinical chemistries, and family history of disease.